They use a dedicated Twitter feed, she says, and recently announced “a new publication that is supposed to be just for jihadi girls.”

“What we’re hearing back is that many of the girls who go end up in a terrible spot,” Ms. Callimachi says, “because once they’re there, they can’t even move around without their husband.”

• Credit risk.

Members of the military can fall into debt just like the rest of us. But the upshot can be far more serious.

In fact, some military leaders call it a matter of national security, says Dave Philipps, our correspondent covering the military.

“Bad credit and unpaid bills can make troops ineligible for a clearance, because those in debt could be more vulnerable to bribery or illegal activity,” he says. And some jobs are unattainable without a clearance.

Those concerns have made the military a forceful critic as the lending industry has persuaded lawmakers in at least eight states to relax rules protecting borrowers who have subpar credit.

The changes make profits even higher on loans to people on the margins, but they also can mean the borrowers — including service members — are saddled with painfully high interest that may only escalate their debt.